CI: Testing with Djangae

11 Oct 2017

The virtues of continuous integration are espoused by many, but actually setting it up continues to be a pain. Recently I found myself needing to setup a CI pipeline for a Djangae project. Djangae is a variation on Django except with additional integrations with Google App Engine. For working with CI I wanted the test output to be machine readable, so either xml or json. Under most circumstances one would be safe to just to run pytest --junitxml=path and move along, but this isn’t one of those circumstances.

The GAE SDK is … fragile. Libraries that help you work with it, like Djangae, do a lot of configuration behind the scenes in order to make it easy. Unfortunately in this situation part of that configuration is dependent on running tests through test. So whenever I’d run pytest it would just break.

I spent hours trying to fiddle with pytest, searching around for plug-ins to fix the issue, stepping through the code to see what was being missed, but to no avail.

Seeing no success on that path I shifted my focus to seeing if there was a way to make it write out results in some machine readable format. That is when I found unittest-xml-reporting by Damien Nozay. This turned what was a multi-hour struggle into a one line change.

First install the library

pip install unittest-xml-reporting

then add it as the test runner for Django (or Djangae).

# in
TEST_RUNNER = 'xmlrunner.extra.djangotestrunner.XMLTestRunner'

If you want the results to be stored in a specific location their is another setting for that too.

# in again
TEST_OUTPUT_DIR = './test_results'

And now you’re done. All your test results will be stored in the desired location and ready for the machine to read.